Crowds can help count crowds: crowd counting in the Caucasus

Just as Tahrir Square in Cairo is the focus of political rallies and demonstrations, so too is Freedom Square in Tbilisi, Georgia. Estimating the number of people in crowds, whether political or concert audiences, can vary widely, depending on the organization conducting the count.

Social Science in the Caucasus (May 31, 2012), a blogsite of The Caucasus Research Resource Centers (CRRC), discusses the controversy in the counting of supporters in Freedom Square at the Bidzina Ivanishvili political rally on May 27. The CRRC said the Georgian police estimated the crowd at 30,000 which differed from the Ivanishvili’s supporters' count of 300,000 and that of independent observers that suggested the figure was 80,000 (http://crrc-caucasus.blogspot.com.au/2012_05_01_archive.html) 

The CRRC article discussed a robust method for counting crowds – originally suggested by Berkeley journalism professor, Herbert Jacobs, in the 1960s. According to the Jacob’s Method, the area in which the crowd is congregating should be divided into smaller sections to determine the proximity of people. If people stand at arm’s distance, one person will cover 0.93 square metres. If people stand close but are not pushing each other, the area of one person is estimated at 0.42 square metres. In a tightly packed crowd, 0.23 square metres is covered by one person (in other words, about four people in one square metre).

CRRC analysed two photographs of the rally at Freedom Square by segmenting the area into 29 “parcels” using geographic information systems (GIS). Its estimation showed that there were 31,000 people in 13 out of the total 29 parcels analysed from the photographs.

CRRC points out that Jacob’s Method is only estimation, plus or minus 20%. And quantity does not always suggest legitimacy! As the CRRC says, “the entire numbers game is a bit problematic.” However, the CRRC thinks the Jacob’s Method is as good as it gets for a quick assessment of crowd numbers.

The article also provides their raw materials used for this exercise with a link to download the spreadsheet so that readers can try out the method themselves.

The CRRC, established in 2003 in the South Caucasus, aims to strengthen social science research and public policy analysis in Georgia, Armenia, and Azerbaijan (http://www.crrccenters.org). The photograph is from their blogsite.

MARTINA NICOLLSis an international aid and development consultant, and the authorof:- Similar But Different in the Animal Kingdom(2017), The Shortness of Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet (2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).